1. Field of the Invention
The present invention relates to a voltage-controlled oscillator, and more particularly, to a voltage-controlled oscillator capable of controlling the biasing current such that the oscillating signal is adjusted.
2. Description of the Related Art
A voltage-controlled oscillator has become a commonly-used device in all kinds of circuits, especially in phase lock loop (PLL). The conventional voltage-controlled oscillator can be referred to U.S. Pat. No. 6,781,471, and U.S. patent applications 20030025566 and 20050248410.
However, due to the conventional voltage-controlled oscillators is hard to get a better biasing current linearity and hard to generate a desired oscillation signal with low power requirement, it is therefore providing a better voltage-controlled oscillator herein.